Fracture incidence after denosumab discontinuation: Real-world data from a large healthcare provider

Treatment of myeloma bone disease: When, how often, and for how long?

The landscape of MM has changed dramatically in recent years. Several new and more effective treatments have been introduced that not only makes patients live longer but also brings them into a deeper remission. This makes the potential total exposure of bone protective treatment much higher but perhaps also less needed. New and more precise imagining techniques have been introduced making detection of bone disease more sensitive, and the introduction of SLiM-CRAB criteria have changed the parameters used in old clinical trials investigating treatment of MM bone disease. New data have also emerged investigating the effect of the RANKL inhibitor denosumab compared to zoledronic acid (ZOL). Randomized trials have investigated longer treatment durations, which becomes more relevant as patients now live longer. In addition in this review, data regarding interval between individual treatment, impact of remission status, new data in relation to rebound after discontinuation and of denosumab, as well as the rational for drug holidays before dental procedures will also be discussed.

Association of Delayed Denosumab Dosing with Increased Risk of Fractures: A Population-Based Retrospective Study

BACKGRUOUND

Inhibitory effects of denosumab on bone remodeling are reversible and disappear once treatment is discontinued. Herein, we examined whether and to what extent delayed denosumab administration is also associated with fracture risk using nation-wide data.

METHODS

The study cohort included women aged 45 to 89 years who were started on denosumab for osteoporosis between October 2017 and December 2019 using data from the Korean Health Insurance Review and Assessment service. Participants were stratified according to the time of their subsequent denosumab administration from the last denosumab administration, including those with within 30 days early dosing (ED30), within the planned time of 180-210 days (referent), within 30-90 days of delayed dosing (DD90), within 90-180 days of delayed dosing (DD180), and longer than 181 days of delayed dosing (DD181+). The primary outcome was the incidence of all clinical fractures.

RESULTS

A total of 149,199 participants included and 2,323 all clinical fractures (including 1,223 vertebral fractures) occurred. The incidence of all fractures was significantly higher in the DD90 compared to reference group (hazard ratio [HR], 1.2; 95% confidence interval [CI], 1.1 to 1.4). The risk of all fracture was even higher in the longer delayed DD180 group (HR, 1.9; 95% CI, 1.6 to 2.3) and DD181+ group (HR, 1.8; 95% CI, 1.5 to 2.2). Increased risks of fractures with delayed dosing were consistently observed for vertebral fractures.

CONCLUSION

Delayed denosumab dosing, even by 1 to 3 months, was significantly associated with increased fracture risk. Maintaining the correct dosing schedule should be emphasized when starting denosumab.

Multiple vertebral fractures after antiosteoporotic medications discontinuation: A comparative study to evaluate the potential rebound effect of denosumab

BACKGROUND

Discontinuation of anti-osteoporotic medications (AOM), except for bisphosphonates (BP), is not favorable for the bone, being especially negative for Prolia® (60 mg denosumab-DMAb). DMAb withdrawal leads to a rapid and significant increase in bone turnover markers, and to an important loss in bone mineral density, which has been associated with an increased risk of multiple vertebral fractures (MVF).

OBJECTIVE

To assess the risk of MVF (≥2 VF) recorded at the same time) after discontinuation of different AOM.

METHODS

A case-control analysis nested in a cohort of new users of DMAb, BP, Teriparatide (TPTD), Strontium Ranelate (SrRan), or selective estrogen receptor modulators (SERM), aged ≥18 years from 2011 to 2018 with ≥1 year of prior available data, was performed using the Pharmacoepidemiological Research Database for the Public Health System (BIFAP) in Spain. Cases were first MVF recorded after AOM initiation (index date). Up to 4 controls per case, matched on index date, age, sex, and location, were randomly selected among non-cases from the cohort. Adjusted conditional OR (AOR) and 95 % CI: between discontinuation of a given AOM (supply of the last prescription ended >90 days before the index date) and occurrence of MVF was assessed compared with their current use and alternatively, with discontinuation of BP, among individuals who did not switch therapy in the study.

RESULTS

A total of 532 incident cases of MVF were identified and matched to 2121 controls (86 % women; median age 73 years). AOR of MVF after DMAb discontinuation was 2.82 (1.73-4.60) compared with DMAb current use. No risk was seen for the other AOM. The AOR was highest between 3 and 9 months after discontinuation of denosumab (8.58; 3.98-18.48) and after >1 year of cumulative use (5- and 11-times increased risk when discontinuing after 1-2 years and 2-5 years of use, respectively). Compared with BP discontinuers, discontinuation of DMAb (2.73, 1.66-4.50), TPTD (2.06, 1.09-3.88) and SrRan (1.93, 1.23-3.05) showed an increased risk of MVF; current use of DMAb showed no protective effect (1.44; 0.95-2.17).

CONCLUSIONS

Discontinuation of DMAb was associated with an immediate increased risk of MVF, especially after longest treatments compared with patients who continued therapy or discontinued BP. Although there were increased risks after discontinuation of other AOM in comparison with first- line therapy (BP), these were not found when the reference was current users. Confounding by indication cannot be discarded. Larger studies should investigate reasons for discontinuation and preventive retreatment options.

Cost-consequence analysis of continuous denosumab therapy for osteoporosis treatment in South Korea

BACKGROUND

Insurance reimbursement provisions in South Korea limit osteoporosis medication availability for patients with T-scores exceeding - 2.5. This study aimed to evaluate the financial impact and fracture prevention of continuous denosumab therapy until a T-score>-2.0 (Dmab-C strategy), versus discontinuation of denosumab after reaching T-score>-2.5 (Dmab-D strategy) in osteoporosis patients.

METHODS

A cost-consequence analysis from a Korean healthcare system perspective was performed using a newly developed Markov model. The incidence of vertebral and non-vertebral fracture, fracture-related deaths, drug costs, and fracture-treatment costs were estimated and compared between Dmab-C and Dmab-D strategy over a lifetime in eligible patients aged 55 years.

RESULTS

Base-case analysis revealed that Dmab-C prevented 32.21 vertebral fracture (VF) and 12.43 non-VF events per 100 patients over a lifetime, while reducing 1.29 fracture-related deaths. Lifetime direct healthcare cost saving per patient was KRW 1,354,655 if Dmab-C replaces Dmab-D. When productivity losses were considered, Dmab-C saved KRW 29,025,949 per patient compared to Dmab-D. The additional treatment costs of Dmab-C could be offset by the higher subsequent treatment costs and fracture treatment costs of Dmab-D. The sensitivity analysis showed consistent patterns with results of the base-case analysis.

CONCLUSION

Continuous treatment using denosumab until osteoporosis patients achieve and maintain a T-score of -2.0 would provide greater clinical and economic benefits in terms of fracture prevention and reduced mortality risks compared to outcomes from discontinuing treatment at a T-score of -2.5 or above. This new treatment strategy would effectively lower the risk of fractures and fracture-related mortality, ultimately leading to lower medical expenses.

Denosumab treatment lapses, discontinuation, and off-treatment fracture risk: A retrospective study of patients with osteoporosis in a real-world clinical setting

INTRODUCTION

The purpose of this study was to retrospectively examine predictors of fracture risk when adult patients experienced a denosumab treatment lapse or discontinuation in a real-world clinic setting.

MATERIALS AND METHODS

Eligible patients were adults who had received ≥2 doses of denosumab at an academic health center in the United States. Demographics, treatment doses, reasons for missed doses, and fractures, were collected retrospectively from electronic health records, from an 8-year period (2010-2018). The number of times each patient incurred a treatment lapse, defined as ≥240 days between two doses (excluding lapse due to discontinuation, death, or transfer of care) was computed. The occurrence of denosumab discontinuation (excluding discontinuation due to death or transfer of care), whether the patient initiated alternative therapy, and the reason for each lapse and discontinuation were collected. Cox proportional hazards models assessed characteristics associated with risk of fracture and treatment discontinuation. A logistic regression model was used to determine if cumulative amount of time off medication (i.e., cumulative lapse time) was associated with a higher likelihood of incurring a fracture.

RESULTS

We included 534 patients: 95 % White, 86 % women, 33 % tobacco users, 13 % diagnosed with diabetes, median age 69 years (Interquartile Range (IQR): 62-77), and median Body Mass Index (BMI) 25 kg/m2 (IQR: 22-28). Thirty-six percent of patients incurred 250 lapses; 10 % discontinued therapy. Dental problems/procedures and logistical barriers were the most common reasons for lapses and discontinuations. Nineteen percent (n = 103) incurred a total of 190 fractures; of these, 121 were osteoporotic, 50 were vertebral. Risk of any, osteoporotic, and vertebral fractures were associated with off-treatment status (hazard ratio [HR] = 1.7, p = 0.043; HR = 2.0, p = 0.026; and HR = 4.2, p = 0.001, respectively) and older age (HR = 1.3, p = 0.015; HR = 1.5, p = 0.001; and HR = 1.8, p = 0.005, respectively). Older age was associated with higher risk of discontinuation (HR = 1.4, p = 0.022). There was a non-significant trend of a nonlinear association between incurring a fracture and cumulative lapse time (p = 0.087).

CONCLUSION

Denosumab treatment lapses are common, and off-treatment status may be associated with a higher risk of fractures. Clinical teams should proactively identify and address adverse effects and potential logistical barriers to reduce the risk of treatment lapses.

Position Statement: Postmenopausal Osteoporosis Treatment Strategies in Korea

Classifying patients with osteoporosis according to fracture risk and establishing adequate treatment strategies is crucial to effectively treat osteoporosis. The Korean Society for Bone and Mineral Research has issued a position statement regarding appropriate treatment strategies for postmenopausal osteoporosis. According to previous fragility fracture history, bone mineral density (BMD) test results, fracture risk assessment tool, and several clinical risk factors, fracture risk groups are classified into low, moderate, high, and very-high-risk groups. In high-risk groups, bisphosphonates (BPs) and denosumab are recommended as first-line therapies. Sequential BP treatment after denosumab discontinuation is required to prevent the rebound phenomenon. In the very high-risk group, anabolic drugs (teriparatide or romosozumab) are recommended as a first-line therapy; sequential therapy with antiresorptive agents is required to maintain BMD gain and reduce fracture risk. Fracture risk was reassessed annually, and the treatment plan was determined based on the results, according to the osteoporosis treatment algorithm for fracture risk.

Cost Effectiveness of Denosumab for Secondary Prevention of Osteoporotic Fractures Among Postmenopausal Women in China: An Individual-Level Simulation Analysis

OBJECTIVE

This study evaluated the cost effectiveness of denosumab versus alendronate for secondary prevention of osteoporotic fractures among post-menopausal women in China.

METHODS

A validated individual-level simulation model of osteoporotic fractures in the Chinese setting was adapted. Allowing both treatment discontinuation and waning effects, the analysis aimed to evaluate the incremental cost-effectiveness ratio of denosumab compared to alendronate by simulating a cohort of previously fractured individuals over the residual lifetime from the healthcare system perspective. Hip, vertebral, and wrist/humeral fractures were tracked along with the associated medical costs and quality-adjusted life-years. Age-related health state utility values, health state utility values of fractures, costs, fracture incidence, and mortality risks for Chinese were used whenever available. Comparative effectiveness data were obtained from a published network meta-analysis. One-way and probabilistic sensitivity analyses were conducted.

RESULTS

In the base case, denosumab was dominated by alendronate with incremental costs of CN¥2743 (US$425) and incremental health outcomes of - 0.20 quality-adjusted life-years at its current price in mainland China. It remained dominated in all one-way sensitivity analysis robustness checks. However, denosumab was cost effective if both drugs did not carry any waning effects. In the probabilistic sensitivity analysis, denosumab remained dominated in all replications.

CONCLUSIONS

Denosumab is not cost effective for preventing secondary fractures among overall postmenopausal women in China. It is advisable to identify alternative denosumab regimens for high-risk subgroups among previously fractured postmenopausal women.

Effect of low dose denosumab on bone mineral density in postmenopausal women with osteoporosis after a transition from 60 mg dose: a prospective observational study

INTRODUCTION

Denosumab is an effective antiresorptive molecule and reduces the risk of fracture in postmenopausal osteoporosis. Cessation of denosumab therapy however is associated with rapid declines in bone mineral density (BMD), rises in bone remodeling, and an increased risk of fracture. We evaluated the effect of low dose denosumab (30 mg every 6 months) on the prevention of bone loss following a switch from standard dose (60 mg of denosumab every 6 months) in a prospective observational study.

METHODS

We recruited 114 women 50-90 years of age with postmenopausal osteoporosis at a moderate fracture risk without prior fragility fractures, who had been on denosumab 60 mg every 6 month. These women switched to low dose denosumab 30 mg every 6 months. Mean percentage change in lumbar spine (LS), femoral neck (FN), total hip (TH) and 1/3 distal radius (1/3RAD) BMD at 12 and 24 months were evaluated. Predictors for change in BMD were explored. Subgroup analysis for patients on denosumab 60 mg every 6 months for <3 years and for ≥3 years before switching to low dose denosumab 30 mg was evaluated.

RESULTS

At 12 months following a switch from 60 mg to 30 mg of denosumab every 6 months we observed an increase in LS BMD mean percentage change (+2.03%, 95% CI 1.18-2.88, p < 0.001). BMD was stable at the hip and radial sites. Age was found to be a predictor of the mean percentage change in LS BMD for the overall sample. At 24 months, there was a further increase in LS BMD mean percentage change (+3.44%, 95% CI 1.74-5.12, p < 0.001), with stable BMD at other skeletal sites. The 12 month mean BMD percentage change at the LS (p = 0.015), FN (p < 0.001), TH (p < 0.001), and 1/3 RAD (p < 0.001) were found to be predictors of the 24 month mean BMD percentage change. No clinical fractures were reported during 24 months of follow up.

CONCLUSION

We observed stable BMD following a switch from denosumab 60 mg every 6 months to 30 mg every 6 months in this prospective observational study conducted in postmenopausal women at a moderate fracture risk.

Screening for the primary prevention of fragility fractures among adults aged 40 years and older in primary care: systematic reviews of the effects and acceptability of screening and treatment, and the accuracy of risk prediction tools

BACKGROUND

To inform recommendations by the Canadian Task Force on Preventive Health Care, we reviewed evidence on the benefits, harms, and acceptability of screening and treatment, and on the accuracy of risk prediction tools for the primary prevention of fragility fractures among adults aged 40 years and older in primary care.

METHODS

For screening effectiveness, accuracy of risk prediction tools, and treatment benefits, our search methods involved integrating studies published up to 2016 from an existing systematic review. Then, to locate more recent studies and any evidence relating to acceptability and treatment harms, we searched online databases (2016 to April 4, 2022 [screening] or to June 1, 2021 [predictive accuracy]; 1995 to June 1, 2021, for acceptability; 2016 to March 2, 2020, for treatment benefits; 2015 to June 24, 2020, for treatment harms), trial registries and gray literature, and hand-searched reviews, guidelines, and the included studies. Two reviewers selected studies, extracted results, and appraised risk of bias, with disagreements resolved by consensus or a third reviewer. The overview of reviews on treatment harms relied on one reviewer, with verification of data by another reviewer to correct errors and omissions. When appropriate, study results were pooled using random effects meta-analysis; otherwise, findings were described narratively. Evidence certainty was rated according to the GRADE approach.

RESULTS

We included 4 randomized controlled trials (RCTs) and 1 controlled clinical trial (CCT) for the benefits and harms of screening, 1 RCT for comparative benefits and harms of different screening strategies, 32 validation cohort studies for the calibration of risk prediction tools (26 of these reporting on the Fracture Risk Assessment Tool without [i.e., clinical FRAX], or with the inclusion of bone mineral density (BMD) results [i.e., FRAX + BMD]), 27 RCTs for the benefits of treatment, 10 systematic reviews for the harms of treatment, and 12 studies for the acceptability of screening or initiating treatment. In females aged 65 years and older who are willing to independently complete a mailed fracture risk questionnaire (referred to as "selected population"), 2-step screening using a risk assessment tool with or without measurement of BMD probably (moderate certainty) reduces the risk of hip fractures (3 RCTs and 1 CCT, n = 43,736, absolute risk reduction [ARD] = 6.2 fewer in 1000, 95% CI 9.0-2.8 fewer, number needed to screen [NNS] = 161) and clinical fragility fractures (3 RCTs, n = 42,009, ARD = 5.9 fewer in 1000, 95% CI 10.9-0.8 fewer, NNS = 169). It probably does not reduce all-cause mortality (2 RCTs and 1 CCT, n = 26,511, ARD = no difference in 1000, 95% CI 7.1 fewer to 5.3 more) and may (low certainty) not affect health-related quality of life. Benefits for fracture outcomes were not replicated in an offer-to-screen population where the rate of response to mailed screening questionnaires was low. For females aged 68-80 years, population screening may not reduce the risk of hip fractures (1 RCT, n = 34,229, ARD = 0.3 fewer in 1000, 95% CI 4.2 fewer to 3.9 more) or clinical fragility fractures (1 RCT, n = 34,229, ARD = 1.0 fewer in 1000, 95% CI 8.0 fewer to 6.0 more) over 5 years of follow-up. The evidence for serious adverse events among all patients and for all outcomes among males and younger females (<65 years) is very uncertain. We defined overdiagnosis as the identification of high risk in individuals who, if not screened, would never have known that they were at risk and would never have experienced a fragility fracture. This was not directly reported in any of the trials. Estimates using data available in the trials suggest that among "selected" females offered screening, 12% of those meeting age-specific treatment thresholds based on clinical FRAX 10-year hip fracture risk, and 19% of those meeting thresholds based on clinical FRAX 10-year major osteoporotic fracture risk, may be overdiagnosed as being at high risk of fracture. Of those identified as being at high clinical FRAX 10-year hip fracture risk and who were referred for BMD assessment, 24% may be overdiagnosed. One RCT (n = 9268) provided evidence comparing 1-step to 2-step screening among postmenopausal females, but the evidence from this trial was very uncertain. For the calibration of risk prediction tools, evidence from three Canadian studies (n = 67,611) without serious risk of bias concerns indicates that clinical FRAX-Canada may be well calibrated for the 10-year prediction of hip fractures (observed-to-expected fracture ratio [O:E] = 1.13, 95% CI 0.74-1.72, I2 = 89.2%), and is probably well calibrated for the 10-year prediction of clinical fragility fractures (O:E = 1.10, 95% CI 1.01-1.20, I2 = 50.4%), both leading to some underestimation of the observed risk. Data from these same studies (n = 61,156) showed that FRAX-Canada with BMD may perform poorly to estimate 10-year hip fracture risk (O:E = 1.31, 95% CI 0.91-2.13, I2 = 92.7%), but is probably well calibrated for the 10-year prediction of clinical fragility fractures, with some underestimation of the observed risk (O:E 1.16, 95% CI 1.12-1.20, I2 = 0%). The Canadian Association of Radiologists and Osteoporosis Canada Risk Assessment (CAROC) tool may be well calibrated to predict a category of risk for 10-year clinical fractures (low, moderate, or high risk; 1 study, n = 34,060). The evidence for most other tools was limited, or in the case of FRAX tools calibrated for countries other than Canada, very uncertain due to serious risk of bias concerns and large inconsistency in findings across studies. Postmenopausal females in a primary prevention population defined as <50% prevalence of prior fragility fracture (median 16.9%, range 0 to 48% when reported in the trials) and at risk of fragility fracture, treatment with bisphosphonates as a class (median 2 years, range 1-6 years) probably reduces the risk of clinical fragility fractures (19 RCTs, n = 22,482, ARD = 11.1 fewer in 1000, 95% CI 15.0-6.6 fewer, [number needed to treat for an additional beneficial outcome] NNT = 90), and may reduce the risk of hip fractures (14 RCTs, n = 21,038, ARD = 2.9 fewer in 1000, 95% CI 4.6-0.9 fewer, NNT = 345) and clinical vertebral fractures (11 RCTs, n = 8921, ARD = 10.0 fewer in 1000, 95% CI 14.0-3.9 fewer, NNT = 100); it may not reduce all-cause mortality. There is low certainty evidence of little-to-no reduction in hip fractures with any individual bisphosphonate, but all provided evidence of decreased risk of clinical fragility fractures (moderate certainty for alendronate [NNT=68] and zoledronic acid [NNT=50], low certainty for risedronate [NNT=128]) among postmenopausal females. Evidence for an impact on risk of clinical vertebral fractures is very uncertain for alendronate and risedronate; zoledronic acid may reduce the risk of this outcome (4 RCTs, n = 2367, ARD = 18.7 fewer in 1000, 95% CI 25.6-6.6 fewer, NNT = 54) for postmenopausal females. Denosumab probably reduces the risk of clinical fragility fractures (6 RCTs, n = 9473, ARD = 9.1 fewer in 1000, 95% CI 12.1-5.6 fewer, NNT = 110) and clinical vertebral fractures (4 RCTs, n = 8639, ARD = 16.0 fewer in 1000, 95% CI 18.6-12.1 fewer, NNT=62), but may make little-to-no difference in the risk of hip fractures among postmenopausal females. Denosumab probably makes little-to-no difference in the risk of all-cause mortality or health-related quality of life among postmenopausal females. Evidence in males is limited to two trials (1 zoledronic acid, 1 denosumab); in this population, zoledronic acid may make little-to-no difference in the risk of hip or clinical fragility fractures, and evidence for all-cause mortality is very uncertain. The evidence for treatment with denosumab in males is very uncertain for all fracture outcomes (hip, clinical fragility, clinical vertebral) and all-cause mortality. There is moderate certainty evidence that treatment causes a small number of patients to experience a non-serious adverse event, notably non-serious gastrointestinal events (e.g., abdominal pain, reflux) with alendronate (50 RCTs, n = 22,549, ARD = 16.3 more in 1000, 95% CI 2.4-31.3 more, [number needed to treat for an additional harmful outcome] NNH = 61) but not with risedronate; influenza-like symptoms with zoledronic acid (5 RCTs, n = 10,695, ARD = 142.5 more in 1000, 95% CI 105.5-188.5 more, NNH = 7); and non-serious gastrointestinal adverse events (3 RCTs, n = 8454, ARD = 64.5 more in 1000, 95% CI 26.4-13.3 more, NNH = 16), dermatologic adverse events (3 RCTs, n = 8454, ARD = 15.6 more in 1000, 95% CI 7.6-27.0 more, NNH = 64), and infections (any severity; 4 RCTs, n = 8691, ARD = 1.8 more in 1000, 95% CI 0.1-4.0 more, NNH = 556) with denosumab. For serious adverse events overall and specific to stroke and myocardial infarction, treatment with bisphosphonates probably makes little-to-no difference; evidence for other specific serious harms was less certain or not available. There was low certainty evidence for an increased risk for the rare occurrence of atypical femoral fractures (0.06 to 0.08 more in 1000) and osteonecrosis of the jaw (0.22 more in 1000) with bisphosphonates (most evidence for alendronate). The evidence for these rare outcomes and for rebound fractures with denosumab was very uncertain. Younger (lower risk) females have high willingness to be screened. A minority of postmenopausal females at increased risk for fracture may accept treatment. Further, there is large heterogeneity in the level of risk at which patients may be accepting of initiating treatment, and treatment effects appear to be overestimated.

CONCLUSION

An offer of 2-step screening with risk assessment and BMD measurement to selected postmenopausal females with low prevalence of prior fracture probably results in a small reduction in the risk of clinical fragility fracture and hip fracture compared to no screening. These findings were most applicable to the use of clinical FRAX for risk assessment and were not replicated in the offer-to-screen population where the rate of response to mailed screening questionnaires was low. Limited direct evidence on harms of screening were available; using study data to provide estimates, there may be a moderate degree of overdiagnosis of high risk for fracture to consider. The evidence for younger females and males is very limited. The benefits of screening and treatment need to be weighed against the potential for harm; patient views on the acceptability of treatment are highly variable.

SYSTEMATIC REVIEW REGISTRATION

International Prospective Register of Systematic Reviews (PROSPERO): CRD42019123767.

Bone loss after denosumab discontinuation is prevented by alendronate and zoledronic acid but not risedronate: a retrospective study

A retrospective study of 121 patients who stopped denosumab (Dmab) then received no treatment (NT), risedronate (RIS), alendronate (ALN), or zoledronic acid (ZOL). Bone density (spine and hip) during and after Dmab discontinuation was measured. Treatment with ALN or ZOL, not NT and RIS, mitigated BMD loss after Dmab discontinuation.

INTRODUCTION

Denosumab (Dmab) discontinuation is associated with bone loss and multiple vertebral fractures. The purpose was to compare bone mineral density (BMD) change in patients following Dmab discontinuation with no subsequent treatment (NT) and three bisphosphonate (BP) treatments: risedronate (RIS), alendronate (ALN), and zoledronic acid (ZOL).

METHODS

In a review of 121 patients aged 71.2 ± 8.1 years, discontinuing Dmab (mean 5.4 doses), 33 received NT and 88 received BP (22 RIS; 34 ALN; 32 ZOL). BMD change after 1 year was compared between groups at the lumbar spine (LS), femoral neck (FN), and total hip (TH). Risk factors for bone loss after Dmab discontinuation were compared between groups and incidence of vertebral fractures was determined.

RESULTS

Following Dmab discontinuation, LS mean change (g/cm2; 95% CI) was for NT: - 0.041 (- 0.062 to - 0.021); RIS: - 0.035 (- 0.052 to - 0.017); ALN: - 0.005 (- 0.020 to 0.009); and ZOL: - 0.009 (- 0.025 to 0.008). Differences in LS were found between NT and ALN (p =  0.015), and NT and ZOL (p=0.037), but not between NT and RIS. The only significant difference in TH was found between NT and ZOL (p 0.034) with no group differences in FN. BMD gains during Dmab treatment were associated with BMD loss after Dmab discontinuation. In a subset, discontinuation after Dmab treatment (> 5 doses) followed by ALN (n = 22) and ZOL (n = 11) showed no difference in BMD. Five of 7 vertebral fractures occurred after Dmab discontinuation in NT.

CONCLUSION

Subsequent treatment with ALN or ZOL but not NT and RIS mitigates BMD loss after Dmab discontinuation.

Gestione clinica della terapia con Denosumab: in chi, quando e come interromperla

Denosumab (Dmab) è un potente farmaco anti-riassorbitivo impiegato per il trattamento dell’osteoporosi al dosaggio di 60 mg sottocute ogni sei 6 mesi. A differenza dei bisfosfonati (BPs), Dmab non si accumula nella matrice ossea e, in caso di ritardo o interruzione delle somministrazioni, è noto un effetto rebound sul turnover osseo, che si traduce in una rapida perdita di Bone Mineral Density (BMD) e in un aumento del rischio di fratture vertebrali, spesso cliniche e multiple. Data la rilevanza clinica di tale fenomeno, si rende quindi necessario per gli specialisti dedicati al trattamento delle patologie osteometaboliche conoscere nel dettaglio quali sono le evidenze attualmente disponibili, nonché le principali raccomandazioni relative alla gestione della terapia anti-osteoporotica con Dmab, con particolare attenzione alla sua interruzione (programmata o accidentale), su cui si focalizzerà la presente Rassegna.

Denosumab Discontinuation

PURPOSE OF REVIEW

To review the pathophysiology, the clinical consequences as well as way of mitigating the effects of denosumab discontinuation.

RECENT FINDINGS

Treatment with denosumab (DMAB) is reversible and upon discontinuation there is a rapid increase in bone turnover and a subsequent bone loss. During this phase of high bone turnover, an increased risk of fractures has been reported. Therefore, treatment with DMAB could be considered life-long. However, side-effects may prompt the need for discontinuation and moreover, treatment with DMAB may have increased BMD to levels where continuing treatment does not provide further fracture risk reduction. Patients stopping DMAB should be offered subsequent antiresorptive treatment with an intense monitoring regimen during the initial year as most of the bone loss occurs within these initial 12 months. In this review, we evaluated the literature published over the past 1 to 3 years investigating DMAB withdrawal with focus on bone turnover markers, bone mineral density, and fracture risk and the transition to other anti-osteoporosis therapies. Furthermore, we summarized the current recommendations of international guidelines. In this review, we evaluated the literature published over the past 1 to 3 years investigating denosumab (DMAB) discontinuation and the transition to other anti-osteoporosis therapies. Additionally, we summarized the current recommendations of international guidelines.

The Role of Bisphosphonates Prior to Denosumab Treatment on Rebound Fractures: A Mini Review

Denosumab is a potent anti-resorptive medication used to treat patients at high risk for osteoporosis; however, its beneficial effects on the skeletal system are quickly reversed after discontinuation. In contrast, bisphosphonates (BPs) are anti-resorptive agents with residual effects on the bone matrix; thus, these are capable of preserving bone mass for a long time. Therefore, subsequent anti-resorptive treatment with BPs is mandatory to prevent rebound fractures. Furthermore, BP administration before denosumab treatment appears to be a reasonable strategy for reducing hyperactivation of bone remodeling. In this review, we summarize the effects of BP administration before denosumab treatment in preventing rebound fractures after denosumab discontinuation.

COVID-19 lockdown negatively impacted on adherence to denosumab therapy: incidence of non-traumatic fractures and role of telemedicine

PURPOSE

Coronavirus disease (COVID-19) lockdowns have impacted on management of osteoporosis and the use of telemedicine is increasingly widespread albeit supported by little evidence so far. The aim of the study is to assess adherence to denosumab and incidence of non-traumatic fractures during the lockdown compared to the pre-COVID-19 year and to explore the effectiveness of telemedicine in the management of osteoporotic patients.

METHODS

Retrospective, longitudinal, single-center study on patients receiving subcutaneous denosumab therapy every 6 months. Each patient was scheduled to undergo 2 visits: one during the pre-COVID-19 period (March 2019-March 2020) and another visit during the lockdown period (March 2020-March 2021). Data on new fractures, adherence, risk factors for osteoporosis and the modality of visit (telemedicine or face-to-face) were collected.

RESULTS

The prevalence of non-adherent patients was higher during the lockdown (35 of 269 patients, 13.0%) than the pre-COVID-19 period (9 of 276 patients, 3.3%) (p < 0.0001). During the lockdown, the number of new non-traumatic fractures was higher than the pre-COVID-19 year (p < 0.0001): 10 patients out of 269 (3.7%) experienced a fragility fracture and 2 patients (0.7%) a probable rebound fracture during the lockdown period, whereas no patient had fragility/rebound fractures during the pre-COVID-19 period. No difference was found in the prevalence of non-adherence and new non-traumatic fractures comparing patients evaluated with tele-medicine to those evaluated with face-to-face visit.

CONCLUSION

Non-adherent patients and new non-traumatic fractures (including rebound fractures) were more prevalent during the lockdown in comparison to the pre-COVID-19 period, regardless of the modality of medical evaluation.

Raloxifene Use After Denosumab Discontinuation Partially Attenuates Bone Loss in the Lumbar Spine in Postmenopausal Osteoporosis

Discontinuation of denosumab (DMab) is associated with decline in bone density. Whether raloxifene can be effective to attenuate bone loss after DMab discontinuation in certain conditions when other antiresorptives cannot be used remains unclear. Data on postmenopausal women with osteoporosis who discontinued DMab treatment after short-term use (1-to-4 doses) at Severance Hospital, Seoul, Korea, between 2017 and 2021 were reviewed. Changes in bone mineral density (BMD) at 12 months after DMab discontinuation was compared between sequential raloxifene users (DR) and those without any sequential antiresorptive (DD) after 1:1 propensity score matching. In matched cohort (66 patients; DR n = 33 vs. DD n = 33), mean age (69.3 ± 8.2 years) and T-score (lumbar spine - 2.2 ± 0.7; total hip - 1.6 ± 0.6) did not differ between two groups at the time of DMab discontinuation. Sequential treatment to raloxifene in DR group attenuated the bone loss in lumbar spine after DMab discontinuation compared to DD group (DR vs. DD; - 2.8% vs. - 5.8%, p = 0.013). The effect of raloxifene on lumbar spine BMD changes remained robust (adjusted β + 2.92 vs. DD, p = 0.009) after adjustment for covariates. BMD loss at femoral neck (- 1.70% vs. - 2.77%, p = 0.673) and total hip (- 1.42% vs. - 1.44%, p = 0.992) did not differ between two groups. Compared to BMD at DMab initiation, DR partially retained BMD gain by DMab treatment in lumbar spine (+ 3.7%, p = 0.003) and femoral neck (+ 2.8%, p = 0.010), whereas DD did not. Raloxifene use after DMab treatment attenuated lumbar spine BMD loss in postmenopausal women with short exposures (< 2 years) to DMab.

Assessment of Strategies for Safe Drug Discontinuation and Transition of Denosumab Treatment in PMO—Insights From a Mechanistic PK/PD Model of Bone Turnover

Denosumab (Dmab) treatment against postmenopausal osteoporosis (PMO) has proven very efficient in increasing bone mineral density (BMD) and reducing the risk of bone fractures. However, concerns have been recently raised regarding safety when drug treatment is discontinued. Mechanistic pharmacokinetic-pharmacodynamic (PK-PD) models are the most sophisticated tools to develop patient specific drug treatments of PMO to restore bone mass. However, only a few PK-PD models have addressed the effect of Dmab drug holidays on changes in BMD. We showed that using a standard bone cell population model (BCPM) of bone remodelling it is not possible to account for the spike in osteoclast numbers observed after Dmab discontinuation. We show that inclusion of a variable osteoclast precursor pool in BCPMs is essential to predict the experimentally observed rapid rise in osteoclast numbers and the associated increases in bone resorption. This new model also showed that Dmab withdrawal leads to a rapid increase of damage in the bone matrix, which in turn decreases the local safety factor for fatigue failure. Our simulation results show that changes in BMD strongly depend on Dmab concentration in the central compartment. Consequently, bone weight (BW) might play an important factor in calculating effective Dmab doses. The currently clinically prescribed constant Dmab dose of 60 mg injected every 6 months is less effective in increasing BMD for patients with high BW (2.5% for 80 kg in contrast to 8% for 60 kg after 6 years of treatment). However, bone loss observed 24 months after Dmab withdrawal is less pronounced in patients with high BW (3.5% for 80kg and 8.5% for 60 kg). Finally, we studied how to safely discontinue Dmab treatment by exploring several transitional and combined drug treatment strategies. Our simulation results indicate that using transitional reduced Dmab doses are not effective in reducing rapid bone loss. However, we identify that use of a bisphosphonate (BP) is highly effective in avoiding rapid bone loss and increase in bone tissue damage compared to abrupt withdrawal of Dmab. Furthermore, the final values of BMD and damage were not sensitive to the time of administration of the BP.

Osteoporotic Fractures among Selective Estrogen Receptor Modulator Users in South Korea: Analysis Using National Claims Database

Background

We evaluated (1) compliance with selective estrogen receptor modulator (SERM) use in postmenopausal women; and (2) the risk of osteoporotic fractures according to compliance and other patient characteristics.

Methods

National claims data of postmenopausal women from January 2013 to December 2014 were reviewed. Demographics, comorbidities, type of medical institution, and patient compliance were investigated. Compliance was measured according to medication possession ratio (MPR) and the patients were classified into compliant (MPR ≥80%) or non-compliant (MPR <80%) groups. Osteoporotic fractures were followed up for 2 years after prescription.

Results

Among 15,166 postmenopausal women, 4,130 were categorized as compliant. Osteoporotic fractures were confirmed in 669 patients. The hip fracture rate in the non-compliant group (0.39%) was marginally higher than that in the compliant group (0.36%; P=0.06). Compared to age 50 to 54 years, age 55 to 59 years showed protection against fractures (hazard ratio [HR], 0.57; 95% confidence interval [CI], 0.379–0.857; P=0.007), while those over 70 years showed a higher risk of fractures (HR, 2.035; 95% CI, 1.485–2.789; P<0.0001 for age 70–74 years; HR, 2.197; 94% CI, 1.588–3.041; P<0.0001 for age 75–79 years; and HR, 3.53; 95% CI, 2.493–4.999; P<0.0001 for age ≥80 years). Patients with mild (HR, 1.29; 95% CI, 1.088–1.530; P=0.0034) and moderate (HR, 1.286; 95% CI, 1.002–1.652; P=0.0486) comorbidities were associated with higher risks of fractures compared to those without comorbidities.

Conclusions

Among postmenopausal women with osteoporosis, only 27.2% complied with SERM therapy. A marginal difference in hip fracture rate was observed between the compliant and non-compliant groups. Older age and severe comorbidities were associated with higher risks of osteoporotic fractures.

Osteonecrosis of the Jaw and Antiresorptive Agents in Benign and Malignant Diseases: A Critical Review Organized by the ECTS

CONTEXT

Antiresorptive therapy significantly reduces fracture risk in patients with benign bone disease and skeletal-related events (SREs) in patients with bone metastases (BM). Osteonecrosis of the jaw (ONJ) is a rare but severe condition manifested as necrotic bone lesion or lesions of the jaws. ONJ has been linked to the use of potent antiresorptive agents, termed medication-related ONJ (MRONJ).

OBJECTIVE

We aimed to identify the differences various aspects of MRONJ among distinct patient categories and provide recommendations on how to mitigate the risk and optimally manage MRONJ in each of them.

METHODS

A working group of the European Calcified Tissue Society (ECTS) and 2 experts performed an updated detailed review of existing literature on MRONJ incidence, characteristics, and treatment applied in bone diseases with variable severity of skeletal insult, ranging from osteoporosis to prevention of cancer treatment-induced bone loss and SREs in cancer patients with BM.

RESULTS

The risk for MRONJ is much higher in patients with advanced malignancies compared to those with benign bone diseases because of the higher doses and more frequent administration of antiresorptive agents in individuals with compromised general health, along with coadministration of other medications that predispose to MRONJ. The overall risk for MRONJ is considerably lower than the benefits in all categories of patients.

CONCLUSION

The risk for MRONJ largely depends on the underlying bone disease and the relevant antiresorptive regimen applied. Physicians and dentists should keep in mind that the benefits of antiresorptive therapy far outweigh the risk for MRONJ development.

Real-World Effectiveness of Anti-Resorptive Treatment in Patients With Incident Fragility Fractures-The STORM Cohort-A Swedish Retrospective Observational Study

Results from real-world evidence (RWE) from the largest healthcare region in Sweden show low uptake of antiresorptive (AR) treatment, but beneficial effect in those receiving treatment, especially for the composite outcome of hip fracture or death. For RWE studies, Sweden is unique, with virtually complete coverage of electronic medical records (EMRs) and both regional and national registries, in a universal publicly funded healthcare system. To our knowledge, there is no previous RWE study evaluating the efficacy of AR treatment compared to no AR treatment after fragility fracture, including data on parenteral treatments administered in hospital settings. The Stockholm Real World Management (STORM) study cohort was established in the healthcare region of Stockholm to retrospectively assess the effectiveness of AR treatment after first fragility fracture using the regional EMR system for both hospital and primary care. Between 2012 and 2018, we identified 69,577 fragility fracture episodes among 59,078 patients, men and women, 50 years and older. Of those, 21,141 patients met inclusion and exclusion criteria (eligible cohort). From these, the final matched study cohort comprised 9840 fragility fractures (cases receiving AR treatment [n = 1640] and controls not receiving AR treatment [n = 8200]). Propensity scores were estimated using logistic regression models with AR treatment as outcome and confounders as independent variables followed by analysis using Cox proportional hazard models. Real world evidence from Sweden's largest healthcare region, comprising a quarter of the Swedish population, show that only 10% of patients receive AR treatment within 1 year after a fragility fracture. Factors associated with not receiving treatment include having a diagnosis of cardiovascular disease. In those treated, AR have positive effects particularly on the composite of fracture and death (any fracture/death and hip fracture/death) in individuals matched for all major confounders. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Discontinuing Denosumab: Can It Be Done Safely? A Review of the Literature

Denosumab, which has been approved for the treatment of osteoporosis since 2010, is a fully humanised monoclonal antibody against a cytokine, receptor activator of nuclear factor kappa B ligand (RANKL), involved in bone resorption. Continued use of denosumab results in a potent and sustained decrease in bone turnover, an increase in bone mineral density (BMD), and a reduction in vertebral and hip fractures. The anti-resorptive effects of denosumab are reversible upon cessation, and this reversal is accompanied by a transient marked increase in bone turnover that is associated with bone loss, and of concern, an increased risk of multiple vertebral fractures. In this review, we outline the effects of denosumab withdrawal on bone turnover markers, BMD, histomorphometry, and fracture risk. We provide an update on recent clinical trials that sought to answer how clinicians can transition away from denosumab safely with follow-on therapy to mitigate bone loss and summarise the recommendations of various international guidelines.

Single pharmacy governed denosumab home administration: optimal adherence by means of a fracture liaison service (FLS) and home care collaboration

Low adherence for denosumab (Dmab, Prolia®) is of major concern. Dutch pharmacies deliveries were calculated recently being 76.5% for a total of 3 injections.

INTRODUCTION

Comparing a model where the prescriber maintains responsibility for adherence (model HC1) (Dmab is purchased and dispensed by patient's own community pharmacy and administered through a home care service (HC)) or an all-in-one model where the pharmacist maintains responsibility for the adherence (Dmab is purchased, dispensed, and administered by a pharmacist's HC) (HC2).

METHODS

We counted the number of Dmab injections, follow-up appointments on time, Dmab administrations delayed to a maximum of 60 days, the number of Dmab discontinuations, and all causes legally traceable under EU privacy act (EDPR).

RESULTS

Home care started by 2014 (study closure in 2021) and included 711 Dmab injections to 256 unique patients: HC1: 536 and HC2: 175 orders. The whole group received on average 2.8 Dmab injections by consistent intervals of about 182 days. Average administration after the latest Dmab injection: 272.8 days (HC1: 362.0 and HC2: 124.0 days). Administration of a subsequent injection > 60 days occurred in 26.6% (HC1: 38.8% and HC2: 6.2%; OR = 9.49). After adjustment for no more than three Dmab injections administered per patient, it occurred in 27.3% (HC1: 51.8% and HC2 4.4%; OR = 23.34).

CONCLUSION

It was possible to achieve 94% adherence for Dmab injections treatment just by transferring the complete supply chain to one pharmacy-initiated home care provider after treatment initiation by either a physician or FLS health care professional.

[Osteoprotection in the management of metastatic prostate cancer: real-world data from Germany and decision guidance]

OBJECTIVE

Osteoprotective medications are a key element not only in the management of bone metastases of castration-resistant prostate cancer (mCRPC) but also of hormone-sensitive prostate cancer (mHSPC). Additionally, osteoprotective drugs can prevent androgen deprivation-induced bone loss. The aim of this study was to illustrate the practice pattern of osteoprotection for prostate cancer patients in Germany.

MATERIAL AND METHODS

We designed an online survey consisting of 16 questions. The survey was sent to the nation-wide working groups "Oncology" and "Uro-Oncology" as well as to colleagues from the departments of urology of University Hospital Schleswig-Holstein (Campus Lübeck), Academic Hospital Brunswick and Technical University of Munich. Furthermore, we developed flow charts for decision guidance for osteoprotection within the different stages of prostate cancer.

RESULTS

Our analysis demonstrates a routine use of osteoprotection in the management of bone metastases of mCRPC. In contrast, osteoprotective medications are less often used for the treatment of bone metastases of mHSPC and for the prevention of androgen deprivation-induced bone loss. Our flow charts depict the different dosages and intervals for the administration of osteoprotective drugs in the different stages of prostate cancer.

CONCLUSIONS

Osteoprotection is not only confined to mCRPC with bone metastases. It plays a crucial role in the management of all stages of metastatic prostate cancer.

Which injected antiosteoporotic medication is worth paying for? A cost-effectiveness analysis of teriparatide, zoledronate, ibandronate, and denosumab for postmenopausal osteoporotic women in China

OBJECTIVE

The purpose of this study was to evaluate the cost-effectiveness of four injected antiosteoporotic medications including teriparatide, zoledronate, ibandronate, and denosumab for postmenopausal osteoporotic women in China.

METHODS

A Markov microsimulation model was used to compare the cost-effectiveness of the four drugs above in Chinese postmenopausal osteoporotic women with no fracture history of hip, vertebral, or wrist at various ages (65, 70, 75, and 80) of therapy initiation from the health care payer perspective.

RESULTS

Denosumab was dominant (ie, lower costs and greater quality-adjusted life-years [QALYs]) compared with other strategies at all ages studied. The incremental cost-effectiveness ratios (ICERs) of zoledronate or ibandronate versus no treatment were $4,482.88/ QALYs or $11,378/QALYs, respectively, at age 65 years, and the results at other ages were similar. In contrast, the incremental cost-effectiveness ratio of teriparatide strategy compared with no treatment exceeded the pre-determined threshold of a willingness-to-pay of $31,512/QALY regardless of the adoption of the patient assistance program at all ages studied, and a threshold analysis showed that teriparatide without patient assistance program became cost-effective when the annual drug cost is decreased to $1,644.87 (current cost: $8,764.65). The cost-effectiveness decision did not change in most of the one-way sensitivity analyses. A scenario analysis considering no offset effect of denosumab showed that zoledronate had the potential to become the optimal option relative to denosumab. In probabilistic sensitivity analyses, the probabilities of denosumab being cost-effective compared with other strategies were 100% at a willingness-to-pay of $31,512/QALY.

CONCLUSIONS

Among postmenopausal osteoporotic women in China, denosumab therapy is cost-effective at all ages examined from the health care payer perspective, compared with teriparatide, zoledronate, or ibandronate. This study will help clinicians and policymakers make better decisions about the relative economic value of osteoporosis treatments in China.

Increased fracture risk after discontinuation of anti-osteoporosis medications among hip fracture patients: A population-based cohort study

BACKGROUND

To compare the risks of major osteoporotic, vertebral, and non-vertebral fractures between patients who discontinued anti-osteoporosis medications.

METHODS

We conducted a comparative effectiveness study with a nationwide population-based cohort study design. Patients aged ≥50 years admitted between 2012 and 2015 for incident hip fractures and receiving denosumab or bisphosphonates with sufficient compliance for at least 1 year were included. Patients were categorized into persistent or non-persistent denosumab or bisphosphonates users based on their subsequent use pattern. The main outcomes were subsequent hospitalizations for a major osteoporotic, vertebral or non-vertebral fracture. Multivariate, time-varying Cox proportional hazards model was used to evaluate the risk of major outcomes.

RESULTS

Compared with persistent denosumab users, non-persistent denosumab users had a significantly higher risk of major osteoporotic fractures (hazard ratio [HR] = 1.60; 95% confidence interval [CI], 1.20-2.14), vertebral fractures (HR = 2.18; 95% CI, 1.46-3.24) and death (HR = 3.57; 95%CI, 2.63-4.84). However, the increased risk of fracture was not found in both persistent and non-persistent bisphosphonates users. Noteworthy, the increased risk of vertebral fractures in non-persistent denosumab users was more pronounced within 1 year post-discontinuation (HR = 2.90; 95% CI, 1.77-4.74) and among patients who discontinued from 2-year denosumab therapy (HR = 3.58; 95% CI, 1.74-7.40).

DISCUSSION

Discontinuation of denosumab resulted in an increased risk of major osteoporotic fractures, especially vertebral fractures. The increased risk tends to reveal within 1 year post-discontinuation and be greater after a longer treatment duration. Notably, only fracture with hospitalization was identified as our research outcome, the real risk of osteoporotic fracture post discontinuation is believed to be higher, especially for vertebral fracture.

Treatment patterns and long-term persistence with osteoporosis therapies in women with Medicare fee-for-service (FFS) coverage

Osteoporosis, a chronic disease, requires long-term therapy. In Medicare-insured women, denosumab persistence was higher than oral bisphosphonate persistence over up to 3 years of follow-up. Longer-term persistence was higher among women who persisted in the first year of therapy.

INTRODUCTION

Osteoporosis, a chronic, progressive disease, requires long-term therapy; this study assessed long-term persistence with anti-resorptive therapies in postmenopausal women.

METHODS

This retrospective cohort study used administrative claims for women with data in the 100% Medicare osteoporosis sample who initiated (index date) denosumab, oral/intravenous (IV) bisphosphonate, or raloxifene between 2011 and 2014 and who had ≥ 1 year (zoledronic acid: 14 months) of pre-initiation medical/pharmacy coverage (baseline). Persistence was assessed from index date through end of continuous coverage, post-index evidence of censoring events (e.g., incident cancer), death, or end of study (December 31, 2015).

RESULTS

The study included 318,419 oral bisphosphonate users (78% alendronate), 145,056 denosumab users, 48,066 IV bisphosphonate users, and 31,400 raloxifene users; mean age ranged from 75.5 years (raloxifene) to 78.5 years (denosumab). In women with at least 36 months of follow-up (denosumab N = 25,107; oral bisphosphonates N = 79,710), more denosumab than oral bisphosphonate initiators were persistent at 1 year (73% vs. 39%), 2 years (50% vs. 25%), and 3 years (38% vs. 17%). Persistence decreased over time for all treatment groups, with denosumab users having the highest persistence in every follow-up time interval at or after 18 months. Women using denosumab, oral bisphosphonates, or raloxifene who persisted in a given year were more likely to remain persistent through the subsequent year.

CONCLUSIONS

Denosumab users persisted longer with therapy than women using other anti-resorptive medications, including oral bisphosphonates. Early persistence may predict long-term persistence. Overall persistence with osteoporosis medications is suboptimal and may impact fracture risk. Efforts to improve first year persistence are needed.

Multiple vertebral fractures after suspension of denosumab. A series of 56 cases

BACKGROUND

Denosumab is a monoclonal antibody approved for the treatment of postmenopausal osteoporosis. The withdrawal of denosumab produces an abrupt loss of bone mineral density and may cause multiple vertebral fractures (MVF).

OBJECTIVE

The objective of this study is to study the clinical, biochemical, and densitometric characteristics in a large series of postmenopausal women who suffered MVF after denosumab withdrawal. Likewise, we try to identify those factors related to the presence of a greater number of vertebral fractures (VF).

PATIENTS AND METHODS

Fifty-six patients (54 women) who suffered MVF after receiving denosumab at least for three consecutive years and abruptly suspended it. A clinical examination was carried out. Biochemical bone remodelling markers (BBRM) and bone densitometry at the lumbar spine and proximal femur were measured. VF were diagnosed by magnetic resonance imaging MRI, X-ray, or both at dorsal and lumbar spine.

RESULTS

Fifty-six patients presented a total of 192 VF. 41 patients (73.2%) had not previously suffered VF. After discontinuation of the drug, a statistically significant increase in the BBRM was observed. In the multivariate analysis, only the time that denosumab was previously received was associated with the presence of a greater number of VF (P = .04).

CONCLUSIONS

We present the series with the largest number of patients collected to date. 56 patients accumulated 192 new VF. After the suspension of denosumab and the production of MVF, there was an increase in the serum values of the BBRM. The time of denosumab use was the only parameter associated with a greater number of fractures.

A Multi-Institutional Randomized Controlled Trial to Investigate Whether Zoledronate Prevents Bone Loss After Discontinuation of Denosumab: The Study Protocol of Denosumab Sequential Therapy (DST) Trial

Background: Though denosumab is an effective treatment for osteoporosis, the rebound effect after discontinuation has drawn investigators' attention. It includes a dramatic loss of gained bone mineral density (BMD) and an increased risk of vertebral fractures. This prospective multi-institutional randomized controlled trial aims to investigate whether zoledronate prevents loss of BMD after discontinuation of denosumab. The trial was registered as Denosumab Sequential Therapy (DST) trial in March 2019 at clinicaltrials.gov, with the identifier NCT03868033.

Methods: The study is conducted at National Taiwan University Hospital and its branches. Patients who have continuously received denosumab treatment for two or more years are surveyed for eligibility. Baseline characteristics and questionnaires of life quality are recorded after recruitment. BMD, circulating levels of bone turnover markers (BTMs), including serum N-terminal propeptide of type 1 collagen (P1NP) and C-terminal telopeptide (CTX), are checked before the stratified randomization to 4 groups. Biological sex and the T-scores are used to create 4 strata. The participants in group 1 adhere to regular denosumab therapy for another 2 years. All the other patients receive on-time zoledronate treatment in the first year. The participants in group 2, 3, and 4 have on-time denosumab, on-time zoledronate and drug holiday in the second year, respectively. BMDs are checked annually. Pre-scheduled checkpoints of BTMs are also arranged. For patient safety, rescue treatment with another injection of zoledronate will be applied to the patients on drug holiday if the CTX levels raise above the pre-specified threshold, 0.573 ng/mL for women and 0.584 ng/mL for men. The primary outcomes are the percentage changes of BMDs in lumbar spine, total hip and femoral neck. The secondary outcomes include the changes of serum level of the BTMs, new osteoporotic fractures, extra zoledronate injections needed in group 4 and the differences of quality of life.

Discussion: We aim to provide evidence whether zoledronate prevents bone loss after denosumab cessation. To our knowledge, the study has the largest sample size. No other randomized controlled study included all the three different treatment strategies and a positive control. It is also the first associated randomized controlled trial outside Europe.

Fractures After Denosumab Discontinuation: A Retrospective Study of 797 Cases

A rebound of osteoclast activity during the 2 years after a treatment or prevention of osteoporosis with denosumab (Dmab) leads to an increased risk of vertebral fractures (VFs). We attempted to identify the risk factors for these VF and to examine the protective role of bisphosphonates. For that, 22 specialists in Switzerland provided data of unselected patients, treated with denosumab for osteoporosis or breast cancer without metastases under aromatase inhibitors, who have received at least two injections of Dmab, with at least 1 year of follow-up after discontinuation. The questionnaire covered separately the periods before, during, and after Dmab treatment, and registered clinical, radiological, and lab data. For the analysis of the risk factors, the main outcomes were the time to the first VF after the treatment, the presence of multiple VFs (MVFs), and the number of VFs. The incidence of VF was 16.4% before, 2.2% during, and 10.3% after the treatment with Dmab. The risk of VF after Dmab discontinuation was associated with an increased risk of non-vertebral fractures. The pretreatment predictors of the post-treatment fracture risk were a parental hip fracture and previous VFs. Further risk factors appeared later, such as low total hip bone mineral density (BMD) during and after denosumab, increased bone resorption markers, and the loss of total hip BMD after the denosumab. Treatment with bisphosphonates, especially after Dmab, had a protective effect. Bisphosphonates given before Dmab did not further decrease the risk of VF in cases who got bisphosphonates after Dmab. This study shows that the risk of VF is poorly predictable before the prescription of denosumab. But during and after the treatment, bone resorption markers and BMD have a significant predictive value. Bisphosphonates after the treatment with denosumab are protective against VFs. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Denosumab Discontinuation in Patients Treated for Low Bone Density and Osteoporosis

Denosumab (DMAB) is a potent antiresorptive treatment used for treatment of osteoporosis and low bone mineral density (BMD) in those at high risk for fracture. In postmenopausal women with osteoporosis, DMAB treatment for 10 years has been studied, with results showing continued gains in BMD, sustained fracture risk reduction, and low risk of adverse events. However, upon discontinuation of DMAB, there is a rapid reversal of effect, with increase in bone turnover, loss of BMD, and in a subset of patients, a greater risk for multiple vertebral fractures.

Circulating miRNAs in bone health and disease

microRNAs have evolved as important regulators of multiple biological pathways essential for bone homeostasis, and microRNA research has furthered our understanding of the mechanisms underlying bone health and disease. This knowledge, together with the finding that active or passive release of microRNAs from cells into the extracellular space enables minimal-invasive detection in biofluids (circulating miRNAs), motivated researchers to explore microRNAs as biomarkers in several pathologic conditions, including bone diseases. Thus, exploratory studies in cohorts representing different types of bone diseases have been performed. In this review, we first summarize important molecular basics of microRNA function and release and provide recommendations for best (pre-)analytical practices and documentation standards for circulating microRNA research required for generating high quality data and ensuring reproducibility of results. Secondly, we review how the genesis of bone-derived circulating microRNAs via release from osteoblasts and osteoclasts could contribute to the communication between these cells. Lastly, we summarize evidence from clinical research studies that have investigated the clinical utility of microRNAs as biomarkers in musculoskeletal disorders. While previous reviews have mainly focused on diagnosis of primary osteoporosis, we have also included studies exploring the utility of circulating microRNAs in monitoring anti-osteoporotic treatment and for diagnosis of other types of bone diseases, such as diabetic osteopathy, bone degradation in inflammatory diseases, and monogenetic bone diseases.

Long-Term Follow-Up of Denosumab Discontinuers with Multiple Vertebral Fractures in the Real-World: A Case Series

Denosumab discontinuation is associated with rapid reversal of bone turnover suppression and with a considerable increase in fracture risk, including a risk for multiple vertebral fractures (MVF). Long-term follow-up of patients who sustained MVF after denosumab discontinuation has not been reported. This case-series was aimed to provide a long-term follow-up on the management and outcome of denosumab discontinuers who initially presented with multiple vertebral fractures. Denosumab discontinuers were identified from a computerized database of a large healthcare provider. Baseline and follow-up clinical, laboratory, and imaging data were obtained from the computerized database and electronic medical records. The post-denosumab discontinuers MVF patients consisted of 12 women aged 71±12. Osteoporotic fractures were prevalent before denosumab discontinuation in 6 of the patients. The majority received bisphosphonates before denosumab. MVF occurred 134±76 days after denosumab discontinuation. The patients were followed for a median of 36.5 (IQR 28.2, 42.5) months after MVF. Two patients passed-away. Two patients suffered recurrent vertebral fractures. Following MVF, patients were treated inconsistently with denosumab, teriparatide, oral, and intravenous bisphosphonates, in various sequences. Two patients underwent vertebroplasty/kyphoplasty. This long-term follow-up of real-world patients with MVF following denosumab discontinuation reveals that management is inconsistent, and recurrent fractures are not uncommon. It calls for clear management guidelines for patients with MVF after denosumab discontinuation and for special attention to this high-risk group.

Risk factors for vertebral fractures and bone loss after denosumab discontinuation: A real-world observational study

BACKGROUND

Denosumab discontinuation without subsequent bisphosphonates (BPs) is associated with bone loss and multiple vertebral fractures.

OBJECTIVE

Identifying risk factors for bone loss and vertebral fractures after denosumab discontinuation.

METHODS

This retrospective study measured the outcome of 219 women with osteoporosis who discontinued denosumab treatment and received subsequent treatment with zoledronate, other BPs or a selective estrogen receptor modulator (SERM), or no therapy. Fracture rate, longitudinal bone mineral density (BMD) changes and bone turnover markers (BTMs) within 2 years after denosumab discontinuation were analysed. Linear regression analysis evaluated loss of BMD and age, BMI (kg/m²), denosumab treatment duration, pre-treatment, prior fracture state, baseline T-scores, use of glucocorticoids or aromatase inhibitors and BMD gains under denosumab therapy.

RESULTS

171 women received zoledronate after denosumab discontinuation, 26 had no subsequent treatment and 22 received other therapies (other BPs or a SERM). Zoledronate was associated with the fewest vertebral fractures (hazard ratio 0.16, p = 0.02) and all subsequent therapies retained BMD at all sites to some extent. Higher BMD loss was associated with younger age, lower BMI, longer denosumab treatment, lack of prior antiresorptive treatment and BMD gain under denosumab treatment. BTM levels correlated with denosumab treatment duration and bone loss at the total hip, but not the lumbar spine.

CONCLUSIONS

Compared to no subsequent therapy, zoledronate was associated with fewer vertebral fractures after denosumab. Further, BMD loss depended on denosumab treatment duration, age, prior BP therapy and BMD gain under denosumab therapy, whereas BTM levels were associated with bone loss at the total hip and denosumab treatment duration.

Denosumab Discontinuation and the Rebound Phenomenon: A Narrative Review

Denosumab is a potent antiresorptive agent that substantially increases bone mineral density and reduces fracture rates at all skeletal sites for as long as it is administered. However, its favorable skeletal effects reverse quickly upon its discontinuation, because of a vast increase of osteoclast number and activity, which leads to a subsequent profound increase of bone turnover above pre-treatment values, a phenomenon commonly described as “rebound phenomenon”. More importantly, most patients experience rapid, profound bone loss due to this burst of bone resorption that may lead in a minority of these patients to occurrence of fractures, especially multiple vertebral fractures. Therefore, subsequent antiresorptive treatment is mandatory, although the optimal regimen is yet to be clarified. In the present review, we outline what is currently known regarding the negative effects of denosumab discontinuation on different aspects of bone status, the factors that may affect them, and strategies to prevent them.

Cost-effectiveness of zoledronic acid compared with sequential denosumab/alendronate for older osteoporotic women in Japan

Among hypothetical cohorts of older osteoporotic women without prior fragility fracture in Japan, we evaluated the cost-effectiveness of two treatment strategies using a simulation model. Annual intravenous zoledronic acid for 3 years was cost-saving compared with biannual subcutaneous denosumab for 3 years followed by weekly oral alendronate for 3 years.

PURPOSE

Osteoporosis constitutes a major medical and health economic burden to society worldwide. Injectable treatments for osteoporosis require less frequent administration than oral treatments and therefore have higher persistence and adherence with treatment, which could explain better efficacy for fracture prevention. Although annual intravenous zoledronic acid and biannual subcutaneous denosumab are available, it remains unclear which treatment strategy represents a better value from a health economic perspective. Accordingly, we examined the cost-effectiveness of zoledronic acid for 3 years compared with sequential denosumab/alendronate (i.e., denosumab for 3 years followed by oral weekly alendronate for 3 years, making the total treatment duration 6 years) among hypothetical cohorts of community-dwelling osteoporotic women without prior fragility fracture in Japan at ages 65, 70, 75, or 80 years.

METHODS

Using a previously validated and updated Markov microsimulation model, we obtained incremental cost-effectiveness ratios (Japanese yen [¥] (or US dollars [$]) per quality-adjusted life-year [QALY]) from the public healthcare and long-term care payer's perspective over a lifetime horizon with a willingness-to-pay of ¥5 million (or $47,500) per QALY.

RESULTS

In the base case, zoledronic acid was cost-saving (i.e., more effective and less expensive) compared with sequential denosumab/alendronate. In deterministic sensitivity analyses, results were sensitive to changes in the efficacy of zoledronic acid or the cumulative persistence rate with zoledronic acid or denosumab. In probabilistic sensitivity analyses, the probabilities of zoledronic acid being cost-effective were 98-100%.

CONCLUSIONS

Among older osteoporotic women without prior fragility fracture in Japan, zoledronic acid was cost-saving compared with sequential denosumab/alendronate.

Should denosumab treatment for osteoporosis be continued indefinitely?

Denosumab was approved for the treatment of postmenopausal osteoporosis in 2010, based on the FREEDOM study, which indicated a benefit in terms of increased bone mineral density and reduced risk of major osteoporotic fracture. In the initial clinical studies it was noted that discontinuation of denosumab can lead to a rebound of bone turnover markers and loss of accrued bone mineral density. An increased risk of fractures (multiple vertebral fractures in particular) associated with discontinuation was noted after approval and marketing of denosumab. For many patients experiencing gain in bone mineral density and fracture prevention while taking denosumab, there is no reason to stop therapy. However, discontinuation of denosumab may happen due to non-adherence; potential lack of efficacy in an individual; where reimbursement for therapy is limited to those with bone mineral density in the osteoporosis range, when assessment reveals this has been exceeded; or patient or physician concern regarding side effects. This review paper aims to discuss these concerns and to summarize the data available to date regarding sequential osteoporosis therapy following denosumab cessation to reduce the risk of multiple vertebral fracture.

The safety profile of denosumab in oncology beyond the safety of denosumab as an anti-osteoporotic agent: still more to learn

INTRODUCTION

Initially endorsed as an antiosteoporotic agent, denosumab ‒ human monoclonal antibody inhibiting the receptor activator of nuclear factor kappa-B ligand (RANKL)‒ has currently shown an anticancer potential, rationalizing its exploitation in oncology. A prerequisite for leveraging denosumab in oncology is a favorable safety profile.

AREAS COVERED

The present review provides an overview of the adverse events of denosumab in oncology, with a focus on hypocalcemia, medication-related osteonecrosis of the jaw, atypical femoral fracture(s), post-denosumab vertebral fractures, increased risk of infections, and excess of second primary cancer. Representative studies addressing the safety and efficacy of denosumab compared to bisphosphonates in oncology are summarized. Critical gaps in the literature concerning the safety of denosumab in oncology are highlighted as opposed to plenty of available safety data on denosumab as an antiosteoporotic agent.

EXPERT OPINION

Despite the generally acceptable safety profile of denosumab in oncology, many issues remain unresolved. Further research is mandatory to counteract current challenges, namely: (i) validation of risk factors for adverse events; (ii) elucidation of the pathophysiology of the adverse events in search of actionable molecular pathways; (iii) illumination of the association of denosumab with increased risk of infections and/or second primary cancer; (iv) establishment of optimal diagnostic, and therapeutic protocols.

Denosumab-associated hypocalcemia: Does gender play a role?

OBJECTIVE

It is well recognized that the presentation, treatment, and outcomes of various diseases may differ between men and women. We recently reported a 7.4% rate of denosumab-associated hypocalcemia in community-dwelling osteoporotic patients. This study sought to investigate the role of gender in this complication.

STUDY DESIGN

Retrospective community-dwelling cohort.

METHOD

The databases of a large health maintenance organization were searched for adult patients treated with denosumab for osteoporosis in 2010-2018. Rates and predictors of denosumab-associated hypocalcemia (serum calcium ≤8.5 mg/mL) were analyzed by gender.

RESULTS

The cohort included 1871 women and 134 men. Compared with the women, the men were characterized by older median age (81 vs. 77 years, p = 0.005), higher likelihood to receive denosumab as a first-line treatment (22% vs. 6%, p < 0.001), less treatment with calcium supplements (42% vs. 53%, p = 0.012), and lower median eGFR level (66.1 vs. 79.8 mL/min/1.73m², p < 0.001). Denosumab-associated hypocalcemia developed in 133 women (7.1%) and 16 men (11.9%) (p = 0.04); the drug was discontinued in 75% and 61%, respectively. The strongest predictors of hypocalcemia in women were levels of pretreatment albumin-adjusted serum calcium (OR 0.08, 95% CI (0.04, 0.14)) and creatinine (OR 2.43, 95% CI (1.45, 4.05)). There were no predictors in men. On propensity matching of 126 men and 126 women, gender was not a predictor of hypocalcemia.

CONCLUSION

Denosumab-treated men were significantly older than treated women and had a lower eGFR and more advanced osteoporosis. These findings suggest that selection bias rather than male genderper se underlies the higher rate of denosumab-associated hypocalcemia in men.

Fracture risk and management of discontinuation of denosumab therapy: a systematic review and position statement by ECTS

CONTEXT

Denosumab discontinuation is characterized by an increase in bone turnover overriding pre-treatment status, a rapid bone loss in the majority and multiple vertebral fractures (VFx) in some patients.

METHODS

A working group of the European Calcified Tissue Society (ECTS) performed an updated systematic review of existing literature on changes of bone turnover, bone mineral density (BMD), and fracture risk after denosumab discontinuation and provided advice on management based on expert opinion.

RESULTS

Important risk factors for multiple VFx following denosumab cessation are prevalent VFx, longer duration off therapy, greater gain in hip BMD during therapy, and greater loss of hip BMD after therapy according to a retrospective analysis of the FREEDOM Extension Study. Case series indicate that prior bisphosphonate therapy mitigates the biochemical rebound phenomenon after denosumab discontinuation, but it is uncertain whether this attenuation prevents BMD loss and fractures. Current evidence indicates partial efficacy of subsequent antiresorptive treatment with results seemingly dependent on duration of denosumab treatment.

CONCLUSIONS

A careful assessment of indications to start denosumab treatment is advised, especially for younger patients. A case for long-term treatment with denosumab can be made for patients at high fracture risk already on denosumab treatment given the favorable efficacy and safety profile. In case of denosumab discontinuation, alternative antiresorptive treatment should be initiated 6 months after the final denosumab injection. Assessment of bone turnover markers may help define the optimal regimen, pending results of ongoing RCTs. Patients having sustained VFx should be offered prompt treatment to reduce high bone turnover.

Delayed Denosumab Injections and Fracture Risk Among Patients With Osteoporosis : A Population-Based Cohort Study

BACKGROUND

Denosumab is effective for osteoporosis, but discontinuation leads to rapid reversal of its therapeutic effect.

OBJECTIVE

To estimate the risk for fracture among users of denosumab who delayed subsequent doses compared with users who received doses on time.

DESIGN

Population-based cohort study.

SETTING

The Health Improvement Network U.K. primary care database, 2010 to 2019.

PATIENTS

Persons aged 45 years or older who initiated denosumab therapy for osteoporosis.

MEASUREMENTS

Observational data were used to emulate an analysis of a hypothetical trial with 3 dosing intervals: subsequent denosumab injection given within 4 weeks after the recommended date ("on time"), delay by 4 to 16 weeks ("short delay"), and delay by more than 16 weeks ("long delay"). The primary outcome was a composite of all fracture types at 6 months after the recommended date. Secondary outcomes were major osteoporotic fracture, vertebral fracture, hip fracture, and nonvertebral fracture.

RESULTS

Investigators identified 2594 patients initiating denosumab therapy. The risk for composite fracture over 6 months was 27.3 in 1000 for on-time dosing, 32.2 in 1000 for short delay, and 42.4 in 1000 for long delay. Compared with on-time injections, short delay had a hazard ratio (HR) for composite fracture of 1.03 (95% CI, 0.63 to 1.69) and long delay an HR of 1.44 (CI, 0.96 to 2.17) (P for trend = 0.093). For vertebral fractures, short delay had an HR of 1.48 (CI, 0.58 to 3.79) and long delay an HR of 3.91 (CI, 1.62 to 9.45).

LIMITATION

Dosing schedules were not randomly assigned.

CONCLUSION

Although delayed administration of subsequent denosumab doses by more than 16 weeks is associated with increased risk for vertebral fracture compared with on-time dosing, evidence is insufficient to conclude that fracture risk is increased at other anatomical sites with long delay.

PRIMARY FUNDING SOURCE

National Clinical Research Center for Orthopedics, Sports Medicine & Rehabilitation.

A Review on the Role of Denosumab in Fracture Prevention

Denosumab is a receptor activator of nuclear factor kappa-Β ligand inhibitor, which suppresses the bone resorption process to preserve bone mass. It is usually recommended to postmenopausal women and men with high fracture risk. With the recent publication of the results from FREEDOM study and its extension, the long-term effect of denosumab in preventing fragility fractures has been put forward. This review aims at summarising the evidence of denosumab in reducing fracture risk and its safety derived from clinical studies. Most of the evidence are derived from FREEDOM trials up to 10 years of exposure. Denosumab is reported to prevent vertebral and non-vertebral fractures. It is also proven effective in Japanese women, patients with chronic kidney diseases and breast cancer patients receiving antineoplastic therapy. Denosumab discontinuation leads to high remodeling, loss of bone mineral density and increased fracture risk. These negative effects might be preventable by bisphosphonate treatment. The safety profile of denosumab is consistent with increased years of exposure. In conclusion, denosumab is a safe and effective option for reducing fracture risk among patients with osteoporosis.

Cost-effectiveness of denosumab for high-risk postmenopausal women with osteoporosis in Thailand

Aims: This study assessed the cost-effectiveness of denosumab for treating postmenopausal women with osteoporosis (PMO) at high risk of fracture in Thailand.Materials and methods: A published Markov cohort cost-effectiveness model was populated with country-specific data as available and other published data as needed. The model used a societal perspective, lifetime horizon, efficacy data from network meta-analysis of trials, and included costs for direct medical and non-medical care, informal care, and osteoporosis treatments to compare denosumab to no pharmacologic treatment (calcium and vitamin D supplements only) and to oral weekly alendronate. The base case (high-risk population) included postmenopausal women with femoral neck T-score ≤-2.5, mean age 65 years at entry, and history of vertebral fracture.Results: High-risk women with osteoporosis using denosumab had the greatest number of life years and quality-adjusted life-years (QALYs) with higher reductions in hip and vertebral fracture incidence compared with patients with no pharmacologic treatment. The incremental cost-effectiveness ratio (ICER) was 119,575 Thai Baht (THB) per QALY for denosumab versus no pharmacologic treatment and 199,186 THB per QALY for denosumab versus alendronate. Among Thai postmenopausal women with high-risk of fractures, denosumab was cost-effective compared with no pharmacologic treatment at a willingness-to-pay threshold of 160,000 THB per QALY. One-way sensitivity analysis showed models were most sensitive to changes in denosumab pricing.Limitations: Data from other countries used when country-specific data were unavailable may not accurately reflect the true experience in Thailand. The model focused explicitly on hip, vertebral, and wrist fractures, and therefore provides a conservative estimate of the overall potential impact of osteoporosis-related fracture. The fracture risk was not adjusted to reflect potential changes in risk after denosumab treatment discontinuation.Conclusions: In Thailand, denosumab offers a cost-effective osteoporosis treatment option versus no pharmacologic treatment in postmenopausal women at high risk of fracture.

Suboptimal medication adherence may favor the progression of vertebral fractures in women with post-menopausal osteoporosis treated with denosumab

BACKGROUND

Medication adherence is a determinant of therapeutic outcomes in osteoporotic patients treated with bisphosphonates. In this monocentric study, we evaluated whether the regular drug administration may influence the effectiveness of denosumab in preventing vertebral fractures (VFs) in real-world clinical practice.

METHODS

Two-hundred and four women (median age 75 years, range: 54-90 years) under treatment with denosumab for post-menopausal osteoporosis were longitudinally evaluated for incident radiological VFs and changes in lumbar spine bone mineral density (BMD) in relationship with medication adherence. All patients were persistent with denosumab treatment (i.e., maximum delay in administration of a single denosumab dose: 90 days). Patients were defined adherent to denosumab therapy when the drug was administered every 6 months ±28 days.

RESULTS

One-hundred-seventy-three patients (84.4%) were adherent to denosumab therapy, whereas the remaining 31 patients (15.6%) received in delay one or more denosumab doses (cumulative delay: 52 days, range 29-183 days). Fourteen patients (6.9%) experienced incident VFs during the follow-up (median duration: 30 months, range: 18-48 months), in relationship with non-adherence to denosumab therapy (hazard ratio 4.44; 95% CI: 1.01-19.47) and smaller increase in lumbar spine BMD (hazard ratio 0.85, 95% CI: 0.76-0.94).

CONCLUSIONS

In post-menopausal women at high risk of fractures, the small delay in the administration of denosumab (i.e., not uncommon in clinical practice) was associated with a significant increase in incidence of VFs. Preservation of standard dosing schedule appears to be an important determinant of denosumab effectiveness in the real-life clinical practice.

Osteoporosis Therapeutics 2020

Numerous safe and efficient drug therapies are currently available to decrease risk of low trauma fractures in patients with osteoporosis including postmenopausal, male, and secondary osteoporosis. In this chapter, we give first an overview of the most important outcomes regarding fracture risk reduction, change in bone mineral density (BMD by DXA) and/or bone markers of the phase III clinical studies of well-established therapies (such as Bisphosphonates, Denosumab or Teriparatide) and also novel therapies (such as Romosozumab or Abaloparatide) and highlight their mechanisms of action at bone tissue/material level. The latter understanding is not only essential for the choice of drug, duration and discontinuation of treatment but also for the interpretation of the clinical outcomes (in particular of eventual changes in BMD) after drug administration. In the second part of this chapter, we focus on the management of different forms of osteoporosis and give a review of the respective current guidelines for treatment. Adverse effects of treatment such as atypical femoral fractures, osteonecrosis of the jaw or influence of fracture healing are considered also in this context.

Zoledronate for the Prevention of Bone Loss in Women Discontinuing Denosumab Treatment. A Prospective 2-Year Clinical Trial

Cessation of denosumab treatment is associated with increases in bone turnover above baseline values and rapid bone loss. We investigated the efficacy of zoledronate to prevent this bone loss in women with postmenopausal osteoporosis who were treated with denosumab (mean duration 2.2 years) and discontinued treatment after achieving osteopenia. Women were randomized to receive a single 5-mg infusion of zoledronate (ZOL) (n = 27) or two additional 60-mg injections of denosumab (Dmab) (n = 30). Both groups were followed for a total period of 24 months. At 24 months lumbar spine-bone mineral density (LS-BMD) was not different from baseline in the ZOL group, but decreased in the Dmab group by (mean ± SD) 4.82% ± 0.7% (p < 0.001) from the 12-month value; the difference in BMD changes between the two groups, the primary endpoint of the study, was statistically significant (p = 0.025). Results of femoral neck (FN)-BMD changes were similar. ZOL infusion was followed by small but significant increases in serum procollagen type 1 N-terminal propeptide (P1NP) and C-terminal telopeptide of type 1 collagen (CTX) during the first year and stabilization thereafter. In the Dmab group, bone turnover marker values did not change during the first 12 months but increased significantly at 15 months and in the majority of women these remained elevated at 24 months. Neither baseline nor 12-month bone turnover marker values were associated with BMD changes in either group of women. In the Dmab group, three patients sustained vertebral fractures (two patients multiple clinical, one patient morphometric) whereas one patient in the ZOL group sustained clinical vertebral fractures 12 months after the infusion. In conclusion, a single intravenous infusion of ZOL given 6 months after the last Dmab injection prevents bone loss for at least 2 years independently of the rate of bone turnover. Follow-up is recommended, because in a few patients ZOL treatment might not have the expected effect at 2 years. © 2019 American Society for Bone and Mineral Research.